I have flown both and really like the new US Envoy suites. Used them MAN-PHL, LGW-CLT, PHL-SJU, etc. The flat bed seats, AVOD system is decent, and they have made major investments in better food and wine. I suggest giving it a go.

My only complaint with UA is that while their seat is layflat, their new set up I was looking at my seat mate, who was facing a different direction and was placed about a foot and a half from me. Not the most comfortable arrangement. I find that US's seats resemble the new DLBE they put in on their 744s. Very comfortable. But don't expect stellar service. After all it is US and UA isn't any better.